Thursday 20 July 2017

Sailfish OS for Sony Xperia X single SIM, model F5121

Interview on the collaboration between Jolla and Sony Open Devices program

The official version is on its way, targeting to support for example MS Exchange Active Sync, Android apps and 20 MPx resolution for the camera. But an unofficial Sailfish OS for Xperia X might become available even sooner via the porters community.

Sailfish OS is an alternative mobile operating system coming from Finland, running on top of Linux Kernel and Mer core. Via this collaboration, Sailfish OS expands its support to cover 64bit ARM.

Interview on Sailfish OS for Sony Xperia X single SIM, model F5121

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Disclaimer: This article is based on a developer interview. Facts shared above the "Editorial" subtopic are checked by Jolla before publishing. "Editorial" part in the end includes only personal opinions of the author. It should be noted that there is a possibility of details being changed until Jolla announce the commercial details, therefore Jolla's advice would be to wait for that announcement before buying the device, just to be completely sure.

Update, August 14, 2017


Jolla announced their target to offer Sailfish OS for Sony Xperia devices in collaboration between Jolla and Sony Open Devices program on Mobile World Congress 2017, Barcelona, Spain on February 2017. Jolla is a Finland based company founded on 2011, developing Sailfish OS mobile operating system.

Sony Open Devices program has its focus on helping 3rd party developers especially on Xperia devices. It was previously known as FreeXperia project under Sony-Ericsson, currently this Sweden based team working as part of Sony Mobile.

This article is a second update to the project based on an interview with Vesa-Matti Hartikainen, program Manager at Jolla. His first update was shared on Jolla Blog in the end of June. I recommend reading that first update prior to the one below.

The partnership

According to Mr. Hartikainen, in practice Jolla has been collaborating with a team based in Sweden. The most of the collaboration takes place online, that being much more convenient, but the developers have also met each other. Currently, Jolla focuses their resources developing on one of the Xperia models only:
Sony Xperia X 32GB single SIM, model F5121
Official color codes: XPERIAX (black), XPERIAXW (white), XPERIAXLG (lime green), XPERIAXRG (rose gold)
Product codes in EU: 1302-9422 (black), 1302-9423 (white), 1302-9426 (lime green), 1302-9427 (rose gold)
Product codes in US: 1302-5762 (black), 1302-5763 (white), 1302-5764 (lime green), 1302-5767 (rose gold)
Other codes used: 1302-4152 / 1302-9401 / 40-27-3921 (black), 1302-8006 (white), 1302-4156 / 1302-9403 / 40-27-3919 (lime green), 1302-4157 / 1302-9406 / 40-27-3917 (rose gold)
[ed.note: Codes have been added after publishing, hence not checked by Jolla. Some retailers use their own product codes which might vary from the ones listed above. Beware of mixing the model to Xperia X 64GB dual SIM (model F5122), a similar looking phone on which it's yet untested if Sailfish OS would run. It might run, or it might not. Also beware of mixing this to Xperia X Performance, or to a smaller phone Xperia X Compact.]
Possible other devices would be announced after this project reaches its goals. Xperia X carries 64bit ARM processor, and this is the first time Sailfish OS expands its support within this processor family. This also means that there's a lot of work and a lot of compromises still. Collaboration is looking good, according to Mr. Hartikainen:

"We believe that our interests have been aligned quite well and this has been a very positive collaboration. We are certainly looking forward to continuing working with them. Sony's Open Devices program forms the basis for the work. Additionally, they have been a great help to us when working on practical issues and technical difficulties."
"Part of the software stack is in 32-bit. Android app support has been the biggest challenge, and we are still working on that. We've had to backport some parts from newer releases of Android to our version to get it to work and we are still solving issues on it."

The Development 

Under the hood, software must be able to communicate with all the hardware on the device. For this, the Linux Kernel version under Sailfish OS core was chosen to be 3.18.

"We always utilize the kernel that comes from the particular device's Android hardware adaptation. These kernels have plenty of patches (device driver code) on top of the vanilla Linux kernel. Amount of code in patches may be tens of thousands of lines of code. Having a newer kernel would mean porting all the patches needed for the HW adaptation to the newer kernel. Having a newer kernel brings very little value to end customers, so we've not seen it worth the effort."

The features 

Xperia X is famous especially of its camera, but some of its features are not part of the Open Devices program being trademarked separately. However, the support for the camera hardware is targeted to be maximized using the available drivers in the Open devices program. 20 MPX resolution is one of those features:

"Currently, we've had 8mpx support for the main camera. We're investigating if we can upgrade it to 20mpx, and it should be doable. Other than that, the camera app will be the same as with the stock Sailfish OS. Obviously, the camera hardware is great and produces great images even at 8mpx."

Jolla is not ready to announce which all Xperia X:s existing features will be supported in the end, but regarding 3rd party features already supported by Sailfish OS, Jolla targets to offer both MS Exchange Active Sync and a decent support for running Android apps:

"Our target is to have same level of Android app compatibility as our other devices have. In our devices most Android apps, for example games utilizing 3D graphics and popular social apps, run just fine and there are 3rd party stores that have wide range of Android apps available. However, Android compatibility isn't still perfect, and there are some apps with known issues.", describes Mr. Hartikainen.

Additionally, and not only regarding Xperia X, Mr. Hartikainen shares that newer Sailfish OS powered devices are having BlueZ 5 that supports BLE. This enables connecting the mobile device to Bluetooth Low Energy accessories like for example ones developed for health care, sports and fitness. Mr. Hartikainen didn't reply if Jolla are themselves developing apps for connecting those or any other wearable accessories, but BLE being supported in general, at least 3rd party developers currently coding for Sailfish OS are sure interested on this possibility.

Installing Sailfish OS on Xperia X to be made by end-customer

Sailfish OS for Sony Xperia X will be available as a separately paid, user installable operating system, updates and support for the software coming from Jolla, a Finland based mobile operating system provider. The community calls this a BYOD model (Bring Your Own Device), software being separately offered.

At least for the first versions, installing Sailfish OS will require unlocking the bootloader on XperiaX. According to the Open Devices program, this might void the warranty. Jolla is doing their best to offer the installing process as easy as possible for the owners of Xperia X single SIM model, yet this arises questions:

Is the cooperation targeting for developers only, or for the masses too? And are there any plans to offer a device with Sailfish OS already pre-installed? Mr. Hartikainen clears this out:

"Currently our focus is on this project and our target is to make downloadable Sailfish OS available to as many of the Sailfish OS fans as possible. We don't want to speculate on any future plans at this point. Further, we can't comment on behalf of Sony. I can understand the interest, but I cannot much expand on what was stated earlier when we announced this. We announced that we want to to provide our licensing customers with a solid hardware solution, and to offer our community a follow up device for the Jolla C. There are good Sailfish OS devices available and planned by our licensees, but at the moment there are many markets where Sailfish OS devices are not yet available. Providing a downloadable Sailfish OS is a practical way to reach also these markets. We have chosen a careful stepwise approach in creation of the downloadable Sailfish OS, and we want expand from most capable tech. enthusiasts towards wider audience, but obviously this requires time to achieve and a lot of maturity in the solution."

The release

"For the Xperia X port there are still some hardware features like bluetooth that are not yet fully functional and we are still working on solving issues for example in Android runtime. We have not yet pushed 2.1.2 release to cbeta, mainly due to 2.1.1 final fixes."

Cbeta is a team of selected community members helping Jolla on testing their software release. After their help and feedback, Jolla considers if the release is ready for wider availability. The rest of the community is of course eager to test the Sailfish OS on Xperia X as soon as possible, and for them Mr. Hartikainen hints about possible 3rd party ports:

"Jolla is focused on bringing Xperia X port of Sailfish OS out with all of the features. That being said, there exists an active community porting Sailfish OS to various devices. They may do their own community version of Xperia X port that could be available earlier than the officially supported version."

   Thanks for this interview Vesku!

Editorial - Should one install Sailfish OS on Xperia X or not

Is one willing to forget the trademarked features of XperiaX on her/his device to be replaced by possibly more intuitive user interface and less commercials by Google on the display. Or to support alternative operating system Sailfish OS development in Finland, instead of the gigantic Google's Android already run by more than 80% of mobile devices worldwide. Sony Mobile plays no role in this decision, but what is great from them is the existence of their Swedish team, supporting development on alternatives and enabling this kind of cooperation in the first place. One couldn't imagine for example Apple's iOS to have such alternatives.

On the selling points, Xperia's camera features were what made Xperia X worth a 600 USD phone when it was first introduced. One should be aware that Sailfish OS camera does not yet support features like smile recognizion or many other neat extras offered by the pre-installed camera, so if you've found those as important in your daily use, stick with Android. Make yourself familiar on what features are trademarked, and be prepared to live without them on the first versions of Sailfish OS on Xperia X.

On the commercials, you might have been annoyed by some notifications popping up on display after installing apps from Google's Play Store. On Sailfish OS, the Android apps have no access to the notifications unless separately allowed by the user. For example I've only allowed those for Whatsapp, to receive a notification when someone sends me a message or tries to reach me there. Also, Android apps have no access to your phone, messages or contacts by default. I find this nice for privacy. If these matters to you, Sailfish OS for Xperia X might be your choice.

On the ideological level, I find Google's current market share too big overall. It's only good to have more diversity - The mobile operating system markets should not be run by one giant and one other mainstream option, meaning the current duopoly between Google's Android and Apple's iOS. Many have tried to step into this territory, including for example Microsoft, Ubuntu, Firefox, Blackberry, Tizen. Sailfish seems to struggle well, being up for 6 years and having financed by 70M USD so far.

On the support / warranty, the choice is somewhat difficult. Maybe not too important, unless you're dependent on official support for the device. Regarding updates of the operating system the support might get even better, looking at all the updates for Sailfish OS so far and notifying that Xperia X was recently discontinued by Sony Mobile. On the warranty, that would be needed if the software was expected to cause hardware failures. Not expected, really.

The price of Xperia X has dropped to half since it first came available, currently being sold for less than 300 EUR in most countries. The price of the Sailfish OS is yet unknown, my personal guess being between 20-50 EUR. The combination is definitely worth that and above, but mobile phone users are not used to pay for their system software, that so far being included in the price of the device.

Experienced hackers could be able to install Sailfish OS on side of the pre-installed Android, enabling dual-boot and selecting the OS right after powering up the device. But for less experienced users, it'll be easier to let Sailfish OS replace the pre-installed Android, at the same time dropping some trademarked features on the phone. For the end-user, the decision is a compromise between features, terms and user interface - but it's also an ideological choice.

On applications and user interface, Sailfish OS is interesting.
I've found it to be a "one-thumb interface" ideal for mobile devices up to 5" display, and the usage patterns are definitely more intuitive than the ones on iOS or Android after getting used to the differences.

Sailfish OS has its lacks especially regarding native apps, but with Android support included I've found decent apps for features like navigation and instant messaging from app stores like Aptoide. Google's Play Store is not included, hence user is expected to get used to 3rd party stores.

In overall, Sailfish OS for Xperia X is definitely worth trying, either as a free community port without Android support and MS Exchange active sync, or as a paid, officially supported operating system with those 3rd party features included.

In any questions, I'm happy to help in the comments section below.

Share and Shout! Your friends might read it.

By: Sailfish OS Reviews
Via: -
Sources: Interview with Vesa-Matti Hartikainen, Jolla
Image source:
Published: 2017-07-20 08:45 UTC
Updated: 2017-08-15 22:15 UTC (product codes)


  1. Thanks for a nice post. I have a few questions:

    So the new 20 mpx camera driver will work with the 3.18 kernel?

    The new AOSP nougat for Xperia X runs on a 4.4 kernel.

    1. Hi Louis, thanks for your questions. In my understanding Jolla is backporting features like the support for 20 Mpx resolution from newer AOSP into their software, and it's not out of the question that they'd build their own kernel based on 3.18 + forking some needed parts from 3.1 or 4.4 into that. After all, 3.4 kernel which Jolla utilized on their first device was somewhat heavily tweaked by them as well.

      What I do know is that 3.18 is abandoned in the Sony Open Devices program regarding Xperia X's camera parts, 4.4 still being WIP, 3.1 being stable but not sure if that version never supported the full resolution on the camera. Personally, I don't mind what the kernel is in the end as long as Jolla keeps their version (mainstream or not) up to date regarding security updates.

    2. Ah I see. When you write 3.1 don't you mean 3.10? :)

  2. I have been watching Jolla for so long that I seem to recall it being part of Nokia. Please GOD give us the software. I will buy whatever I have to, just give me access 0_o

    I have been dieing for a SailfishOS phone stable for use in the USA. If that day is here I can add it to my collection of epic Linux shit N9/n900/n810/n800... Xperia X?

  3. Interested only paid Sailfish OS with all licences required for all functions available and fully working! N0 bullshit, otherwise, Jolla sailfish OS as boat is stranded.

  4. Nothing destroys a "community" like lack of communication (are they still working on something I am invested in), uncertainty (maybe this device, maybe in the summer) and clique building (cbeta, Those Who Are Worthy). I very much support Jolla all the way from Meego and I also very much understand the difficulty of their business reality, but the communication has always been spotty. Things just don't flow as if you are a part, which bites people who are part of open-source development or who made a deliberate choice to support an underdog platform. Perhaps it's just the awkward "Finnish way" of communicating minimally, and then saying the wrong things or having statements come out ambiguously or without needed clarification.

    Anyway, a lot of us devs and end-users are rooting for the company and waiting for the general availability of a device that's not running Android or iOS. All my sympathy to the devs working on this at Jolla, who don't deserve to take flak from all sides for the conditions they have to work in.

    1. I agree. To make something out of this, what can we do to make things better? Are there any certain questions you'd like me to try to spread some light on? I've been following Jolla's communication since the beginning, and the community feedback on that as well. What has happened in a longer run is that Jolla has became much more careful, publishing less schedules, no updates to their development roadmap, less promises overall. Clarification is still an issue too, but I've seen that part getting slightly better. As a company, Jolla has turned more into b2b2g / b2g marketing, at the same time trying to hold onto their dev community who are mostly customers. About this article, assuming the collaboration has been going on well, I was expecting for example that Jolla had all the supported features in their knowledge by now. Anyway, let's work on all the comms in a constructive way. Thanks for your great comment!

  5. I would prefer LineageOS and a rooted phone to be honest.